Communication system, communication apparatus, communication method and computer program
By deciding positions of frequencies used via a relay station by a system in advance for assignment of boundary frequencies, frequencies of a central frequency more likely to be affected by the relay station are also mapped by avoiding a signal thereof. Alternatively, an adjacent cell whose central frequency is affected changes depending on a position of the relay station and thus, locations set to be highly likely to interfere with the central frequency of the adjacent cell is reduced by setting a region of the boundary frequencies permitted to the relay station in accordance with the position of the relay station.
1. A base station in a first cell, the base station comprising:
a position information holding circuit that stores first position information of each relay station in the first cell;
a backhaul communication circuit that receives second position information of each relay station in a second cell from a second base station in the second cell, the position information holding circuit storing the second position information of each relay station in the second cell;
a relay station frequency assignment circuit that assigns frequency bands for each relay station of the first cell in accordance with the first position information and the second position information;
a notification circuit that notifies the second base station in the second cell of interference information that includes at least a level of interference from the second cell, a level of power for managing radio resources, or the determined frequency bands; and
a scheduling circuit that schedules the radio resources in the first cell according to the interference information, wherein
each of the first cell and the second cell include a center region and a boundary region.
2. The base station according to claim 1 , wherein the first cell is adjacent to the second cell.
3. The base station according to claim 2 , wherein each center region uses a central frequency and each boundary region uses a boundary frequency.
4. The base station according to claim 3 , wherein each of the first cell and the second cell permits installation of a relay station that relays communication between a base station and a mobile station.
5. The base station according to claim 4 , wherein
an assignment to the relay station in the first cell is restricted to a restricted band on the first cell side, and
a frequency to the mobile station in the second cell is assigned by avoiding the restricted band or by lowering a degree of priority on the second cell side.
6. The base station according to claim 4 , wherein
the notification circuit notifies the second base station of a restricted band, and
the scheduling circuit schedules the radio resources while conforming to the restricted band.
7. The base station according to claim 6 , further comprising a relay station frequency assignment decision circuit that decides the restricted band of boundary frequencies to be assigned to the relay station.
8. The base station according to claim 6 , wherein when the second base station is notified of the restricted band, the scheduling circuit assigns a central frequency of the first cell by avoiding the restricted band of the adjacent cell or lowering an order of priority thereof.
9. A communication method, performed by a base station in a first cell, the communication method comprising:
storing, by a position information holding circuit, first position information of each relay station in the first cell;
receiving, by backhaul communication circuit, second position information of each relay station in a second cell from a second base station in the second cell;
storing, by the position information holding circuit, the second position information of each relay station of the second cell;
assigning, by a relay station frequency assignment circuit, frequency bands for each relay station of the first cell in accordance with the first position information and the second position information;
notifying, by a notification circuit of the base station, the second base station in the second cell of interference information that includes at least a level of interference from the second cell, a level of power for managing radio resources, or the determined frequency bands; and
scheduling, by a scheduling circuit of the base station, the radio resources in the first cell according to the interference information, wherein
each of the first cell and the second cell include a center region and a boundary region.
10. The communication method according to claim 9 , wherein
the first cell is adjacent to the second cell, and
each center region uses a central frequency and each boundary region uses a boundary frequency.
11. The communication method according to claim 10 , wherein each of the first cell and the second cell permits installation of a relay station that relays communication between a base station and a mobile station.
12. The communication method according to claim 11 , further comprising:
restricting an assignment, to the relay station in the first cell, to a restricted band on the first cell side, and
assigning a frequency to the mobile station in the second cell by avoiding the restricted band or by lowering a degree of priority on the second cell side.
13. The communication method according to claim 12 , further comprising deciding the restricted band of boundary frequencies to be assigned to the relay station.
14. The communication method according to claim 12 , further comprising:
when the second base station is notified of the restricted band, the scheduling circuit assigns a central frequency of the first cell by avoiding the restricted band of the adjacent cell or lowering an order of priority thereof.
15. A non-transitory computer readable medium storing computer readable instructions that, when executed by a base station in a first cell, the base station including circuitry, causes the base station to:
store first position information of each relay station in the first cell;
receive second position information of each relay station in a second cell from a second base station in the second cell;
store the second position information of each relay station in the second cell;
assign frequency bands for each relay station of the first cell in accordance with the first position information and the second position information;
notify the second base station in the second cell of interference information that includes at least a level of interference from the second cell, a level of power for managing radio resources, or the determined frequency bands; and
schedule the radio resources in the first cell according to e interference information, wherein
each of the fir t cell and he second cell include a center region and a boundary region.
16. The non-transitory computer readable medium according to claim 15 , wherein
the first cell is adjacent to the second cell, and
each center region uses a central frequency and each boundary region uses a boundary frequency.
17. The non-transitory computer readable medium according to claim 16 , wherein each of the first cell and the second cell permits installation of a relay station that relays communication between a base station and a mobile station.
18. The non-transitory computer readable medium according to claim 17 , wherein
an assignment to the relay station in the first cell is restricted to a restricted band on the first cell side, and
a frequency to the mobile station in the second cell is assigned by avoiding the restricted band or by lowering a degree of priority on the second cell side.
19. The non-transitory computer readable medium according to claim 17 , wherein the base station is further caused to:
notify the second base station of a restricted band; and
schedule the radio resources while conforming to the restricted band.